Aqueous Colloidal Dispersions of Polyaniline Particles

1989 ◽  
Vol 173 ◽  
Author(s):  
Steven P. Armes ◽  
Mahmoud Aldissi
Keyword(s):  
Aqueous Media ◽  
Colloidal Dispersions ◽  
Polymeric Surfactant ◽  
Poly Vinyl Alcohol ◽  
Rice Grain ◽  
Chemical Polymerization ◽  
Cast Films ◽  
Bulk Powder ◽  
Solution Cast ◽  
Aniline Polymerization

ABSTRACTColloidal polyaniline has been prepared in acidic aqueous media by a modified chemical polymerization of aniline in the presence of a tailor-made polymeric surfactant. The surfactant which acts as a steric stabilizer used in this study is derivatized poly(vinyl alcohol-co-vinyl acetate). This surfactant contains pendant aniline units which participate in the aniline polymerization, resulting in the formation of sterically-stabilized polyaniline particles which have a non-spherical “rice-grain” morphology.It is shown that this novel form of polyaniline is more processable than the bulk powder that is normally obtained from a conventional chemical synthesis. The solid-state conductivity of solution-cast films or compressed pellets of these dispersions is surprisingly high (⋍ 1 S/cm), despite the presence of the insulating outer layer of chemically-grafted stabilizer.

scholarly journals Self-Healing Polymer-Clay Hybrids by Facile Complexation of a Waterborne Polymer with a Clay

2021 ◽  
Author(s):  
Aranee Pleng Teepakakorn ◽  
Makoto Ogawa
Keyword(s):  
Vinyl Alcohol ◽  
Aqueous Media ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Self Healing ◽  
Soluble Polymer ◽  
Water Soluble Polymer ◽  
Smectite Clay

Water-induced self-healing materials were prepared by the hybridization of a water-soluble polymer, poly(vinyl alcohol), with a smectite clay by mixing in an aqueous media and subsequent casting. Without using chemical...

Melting of nanoporous-crystalline and Co-Crystalline solution cast films of Poly(2,6-dimethyl-1,4-phenylene) oxide

Polymer ◽  
2021 ◽  
pp. 123935
Author(s):  
Baku Nagendra ◽  
Manohar Golla ◽  
Christophe Daniel ◽  
Paola Rizzo ◽  
Gaetano Guerra
Keyword(s):  
Cast Films ◽  
Phenylene Oxide ◽  
Solution Cast ◽  
Crystalline Solution

Cellulose acetate/poly(vinyl alcohol) hybrid fibrous mat containing tetracycline hydrochloride and phenytoin sodium: Morphology, drug release, antibacterial, and cell culture studies

2018 ◽  
Vol 33 (6) ◽  
pp. 597-611 ◽  
Author(s):  
Hamed Souriyan-Reyhani pour ◽  
Ramin Khajavi ◽  
Mohammad Esmaeil Yazdanshenas ◽  
Payam Zahedi ◽  
Mohammad Mirjalili
Keyword(s):  
Drug Release ◽  
Cellulose Acetate ◽  
Vinyl Alcohol ◽  
Aqueous Media ◽  
Tetracycline Hydrochloride ◽  
Diameter Distribution ◽  
Poly Vinyl Alcohol ◽  
Release Kinetic ◽  
Phenytoin Sodium ◽  
20 Nm

The objective of this study was to introduce an electrospun hybrid fibrous mat (a dual-fiber drug delivery system) based on cellulose acetate and poly(vinyl alcohol) containing tetracycline hydrochloride and phenytoin sodium, respectively. Characterization of samples was carried by morphology, drug release, cell cytotoxicity, adhesion, antibacterial property, and wettability investigations. The results showed a uniform shape and a narrow diameter distribution of fibers (between 160 ± 20 nm) for fabricated cellulose acetate/poly(vinyl alcohol) hybrid fibrous mat. The tetracycline hydrochloride release from cellulose acetate significantly decreased due to gel formation of poly(vinyl alcohol) in aqueous media. The best fit for drug release kinetic of hybrid sample was Higuchi model. Sample with tetracycline hydrochloride and phenytoin sodium drugs showed improved cell growth, viability, and antibacterial activity against Escherichia coli (~89%) and Staphylococcus aureus (~98%) in comparison with sample without drugs. The hydrophilic property of cellulose acetate/poly(vinyl alcohol) fibrous sample containing the drugs was also remarkable (~45°). To consider the obtained results, the presented hybrid fibrous mat shows a high potent for biomedical applications.

Photoinduced Absorption Spectroscopy of Poly-3-Alkylthiophenes

1992 ◽  
Vol 247 ◽  
Author(s):  
C. Botta ◽  
S. Luzzati ◽  
A. Bolognesi ◽  
R. Tubino ◽  
A. Borghesi
Keyword(s):  
Absorption Spectroscopy ◽  
Near Infrared ◽  
Laser Intensity ◽  
Electronic States ◽  
Chain Mechanism ◽  
Photoinduced Absorption ◽  
Polymer Aggregates ◽  
Cast Films ◽  
Solution Cast

ABSTRACTWe report a study of the near infrared photoinduced absorption of a series of poly -3-decylthiophene with different supermolecular organization as solution cast films, good solvent and aggregated bad solvent solutions.Photoinduced subgap electronic states are detected both in the solid and in solutions independently from the presence of polymer aggregates. The study of the photoinduced activity Δ/T on the laser intensity I indicate a I0.6 dependence for the films and a I0.95 dependence for the solutions. This is the evidence that the photoinduced states are generated in the solid via an inter-chain mechanism while in the solution via an intra-chain mechanism.A possible role of the solvent into the photoexcitation pathway is discussed.

Synthesis and thermal stability studies of polyaniline/silver nanocomposite based on reduction of silver ions using polyaniline

2011 ◽  
Vol 23 (7) ◽  
pp. 513-517 ◽  
Author(s):  
Mohsen Ghorbani ◽  
Mohammad Soleimani Lashkenari ◽  
Hossein Eisazadeh
Keyword(s):  
Thermal Stability ◽  
Chemical Structure ◽  
Aqueous Media ◽  
Silver Ions ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Stability Studies ◽  
Scanning Calorimetry ◽  
Chemical Polymerization ◽  
Silver Nanocomposite

This study investigated the preparation and properties of polyaniline/silver (PAn/Ag2O) nanocomposite in aqueous media by chemical polymerization of aniline in the presence of ammonium peroxydisulphate as an oxidant. The products were investigated in terms of morphology, chemical structure, thermal stability and thermal degradation using scanning electron microscopy, Fourier transform infrared, thermal gravimetric analysis and differential scanning calorimetry, respectively. The results indicated that the properties of products were dependent on the nanocomposite structure.

scholarly journals Cryostructuring of Polymeric Systems. 49. Unexpected “Kosmotropic-Like” Impact of Organic Chaotropes on Freeze–Thaw-Induced Gelation of PVA in DMSO

Gels ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 81 ◽  
Author(s):  
Vladimir Lozinsky ◽  
Olga Kolosova ◽  
Dmitrii Michurov ◽  
Alexander Dubovik ◽  
Viktor Vasil’ev ◽  
...  
Keyword(s):  
Guanidine Hydrochloride ◽  
Aqueous Media ◽  
Poly Vinyl Alcohol ◽  
Gel Formation ◽  
Polymeric Systems ◽  
Freeze Thaw ◽  
Structural Regularity ◽  
Huggins Constant ◽  
Key Factor ◽  
Activation Heat

Urea (URE) and guanidine hydrochloride (GHC) possessing strong chaotropic properties in aqueous media were added to DMSO solutions of poly(vinyl alcohol) (PVA) to be gelled via freeze–thaw processing. Unexpectedly, it turned out that in the case of the PVA cryotropic gel formation in DMSO medium, the URE and GHC additives caused the opposite effects to those observed in water, i.e., the formation of the PVA cryogels (PVACGs) was strengthened rather than inhibited. Our studies of this phenomenon showed that such “kosmotropic-like” effects were more pronounced for the PVACGs that were formed in DMSO in the presence of URE additives, with the effects being concentration-dependent. The additives also caused significant changes in the macroporous morphology of the cryogels; the commonly observed trend was a decrease in the structural regularity of the additive-containing samples compared to the additive-free gel sample. The viscosity measurements revealed consistent changes in the intrinsic viscosity, Huggins constant, and the excess activation heat of the viscosity caused by the additives. The results obtained evidently point to the urea-induced decrease in the solvation ability of DMSO with respect to PVA. As a result, this effect can be the key factor that is responsible for strengthening the structure formation upon the freeze–thaw gelation of this polymer in DMSO additionally containing additives such as urea, which is capable of competing with PVA for the solvent.

Resonant Raman Scattering of Poly-3-Alkylthiophenes

1989 ◽  
Vol 173 ◽  
Author(s):  
C. Botta ◽  
S. Luzzati ◽  
A. Bolognesi ◽  
M. Catellani ◽  
S. Destri ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Electronic Transition ◽  
Vibrational Frequency ◽  
Strongly Coupled ◽  
Cast Films ◽  
Scattering Measurements ◽  
Solution Cast ◽  
Resonant Raman ◽  
Resonant Raman Scattering

ABSTRACTWe report Raman scattering measurements on poly-3-heptylthiophene and poly-3-undecylthiophenes both on resonance and preresonance conditions. We have studied different samples as solutions ,solution cast films and electrosynthetized as grown films. Our results indicate that the vibrational frequency of the mode which is strongly coupled to the π - π* electronic transition is sensible to “small” torsions between thiophenes rings , which do not necessarly interrupt completely the conjugation path.

Molecular Dynamics of "Hairy Rod" Molecules in the Solid State: Poly(.gamma.-methyl L-glutamate)-co-(.gamma.-n-octadecyl L-glutamate) in Solution-Cast Films

1995 ◽  
Vol 28 (16) ◽  
pp. 5487-5497 ◽  
Author(s):  
A. Schmidt ◽  
S. Lehmann ◽  
M. Georgelin ◽  
G. Katana ◽  
K. Mathauer ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Solid State ◽  
Cast Films ◽  
Solution Cast

Solution-cast films of poly(3,4-ethylenedioxythiophene) as ion-to-electron transducers in all-solid-state ion-selective electrodes

2004 ◽  
Vol 97 (2-3) ◽  
pp. 182-189 ◽  
Author(s):  
Mercedes Vázquez ◽  
Petter Danielsson ◽  
Johan Bobacka ◽  
Andrzej Lewenstam ◽  
Ari Ivaska
Keyword(s):  
Solid State ◽  
Ion Selective Electrodes ◽  
Cast Films ◽  
Solution Cast
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